Movable Scaffolding

ABSTRACT

A movable scaffold ( 20 ) has one or more fixed work platforms ( 21 ). The scaffold frame element has four upright tubular corner members ( 1 ) connected by tubular cross-members ( 2, 2   a,    2   b ). Each tubular corner member has a bottom end provided with a wheel ( 15 ) for allowing a displacement of the scaffold. The scaffold is provided with elements for adjusting its height. Between each tubular corner member ( 1 ) and the wheel ( 15 ) at its bottom end are provided vertical adjustment elements ( 5 ) to enable an individual vertical adjustment of each wheel relative to its associated tubular corner member ( 1 ) while effecting a displacement of the scaffold ( 20 ), the scaffold being thus safely movable even on rough foundation.

This application is a U.S. national stage application of International App. No. PCT/FI2005/050433, filed Nov. 23, 2005, the disclosure of which is incorporated by reference herein, and claims priority on Finish App. No. 20050397, filed Apr. 18, 2005.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates to a movable scaffold.

In prior known scaffolds, having the four corners thereof provided with an adjustment feature, such as e.g. in a scaffold described in U.S. Pat. No. 4,293,054 which has a vertically movable hoisting platform, the scaffold has its vertical adjustment elements consisting of adjustable legs not allowing for a displacement of the scaffold during or after the adjustment procedure. With these scaffolds, the disengagement/engagement of adjustment in rough terrain causes the scaffold to topple over.

SUMMARY OF THE INVENTION

An object of the invention is to eliminate this drawback and to provide a scaffold capable of being displaced as well as adjusted from four corners simultaneously even in terrain with major height differences. The scaffold is safe during its displacement, nor does it topple over.

The invention will now be described in more detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows schematically one scaffold of the invention in erected condition.

FIG. 2 shows one structural element for the scaffold of FIG. 1.

FIG. 3 shows in more detail one vertical adjustment mechanism useful in a scaffold of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A scaffold 20 shown in FIG. 1 comprises tubular corner members 1, which are connected to each other at the ends of the scaffold by means of substantially horizontal tubular cross-members 2, preferably by welding, thus producing gable elements 23 (see FIG. 2). The tubular material comprises preferably aluminum, e.g. aluminium of alloy T6. In this exemplary case, the aluminium tube has a diameter of 50 mm and a wall thickness of 2 mm. The gable elements 23 present at the opposite ends of the scaffold are connected to each other by means of work platforms 21 and by substantially horizontal rear-side tubes 2 b and diagonal front-side bracing tubes 2 b. The passage between work platforms at various levels is provided by means of ladders 22, extending adjacent to the work platforms between the gable elements 23 within a frame structure established by the tubular corner members 1 and the tubular cross-members 2, 2 a, 2 b connecting the same. Each tubular corner member has its bottom end provided with a wheel 15 for enabling a displacement of the scaffold. When the scaffold is in its erected position, the wheels are locked and thus prevent an inadvertent displacement of the scaffold. In addition, the scaffold can be fitted with adjustable extra bracing legs 24 for ensuring that the erected scaffold stays securely upright, especially in the case of high-rise scaffolds, and/or for preventing its inadvertent movement. The scaffold is intended for use both outdoors with its top work platform at the height of 8 m according to standard EN1004 and indoors with its top work platform at the height of 12 m according to standard EN1004. A ballast for steadying the scaffold is indicated by reference numeral 25.

A vertical adjustment between the wheel 15 and a tubular corner member 1 associated therewith during erecting the scaffold and/or during moving the scaffold to another position on an uneven foundation is implemented by means of a vertical adjustment mechanism 5 depicted more closely in FIG. 3. As shown in FIG. 3, the vertical adjustment mechanism comprises a casing element 5 a attached to the scaffold's 20 gable element 23, and a lifting element 5 b movable relative to the casing element in the longitudinal direction of the casing element. A movement of the lifting element 5 b relative to the casing element 5 a can be effected e.g. mechanically or hydraulically. To the casing element 5 is preferably welded a connecting piece 14, to which is in turn attached, preferably likewise by welding, an attachment element 4, having its bottom end provided with a hook member 4 a which is adapted to bear from below against the substantially horizontal tubular cross-member 2 of the scaffold's gable element. The attachment element 4 is adapted to be clamped to at least one tubular cross-member 2 with a clamping means 3, e.g. a bolt, the attachment element 4 and the tubular cross-member 2 having necessary holes drilled therein for this purpose. In the depicted embodiment, the attachment element 4 is connected to three lowermost tubular cross-members 2 of the scaffold's gable element. In the exemplary case, the vertical adjustment mechanism 5 has a height of 114 mm, it has a lifting height of 760 mm and a lifting load of 900 kg max. In the exemplary case, the attachment element 4 is made of steel and 750 mm in length, 10 mm in thickness, and 50 mm in width.

The wheel 15 has connected therewith an adjustment tube 9, which is preferably made of steel and disposed inside a tubular corner member 1 to travel longitudinally relative to the tubular corner member. By way of example, the adjustment tube is 45 mm in diameter, 1800 mm in length, and has a wall of 3 mm and has preferably a steel flange 10 welded thereto, said flange having holes drilled in its corners. The wheel 15 has its body 13 fitted respectively with a flange element 12 with matching holes drilled in its corners. The flange elements 10, 12 are coupled to each other with bolts 11. The lifting element 5 b is parallel to the adjustment tube 9 and has its bottom end provided with elements 6-8 for displacing the wheel 15 and its associated adjustment tube 9 relative to the tubular corner member 1 in the process of moving the lifting element 5 b relative to the casing element 5 a. The guide elements at the lifting element's 5 b bottom end include a tubular member 8 preferably of steel, which is linked, e.g. by way of a T-shaped bracket 7, to a plate member 6 mounted on the lifting element's bottom end. The adjustment tube 9 is extended through the tubular member 8 to the interior of the tubular corner member 1. In the exemplary case, the tubular member has a diameter of 51 mm, a height of 100 mm, and a wall thickness of 3 mm.

In the process of moving the scaffold, the vertical adjustment mechanism 5 provided in each corner can be operated whenever necessary by means of a crank 16, the adjustment tube 9 moving within the tubular corner member up or down depending on the rotating direction of the crank, and the wheel 15 is moving concurrently relative to the scaffold frame, thus adapting the wheel 15 to undulations of terrain to maintain the scaffold always essentially upright throughout the displacement. The scaffold is intended for a slow walking-pace movement by human effort, whereby the moving crew has time to respond to variations in terrain. 

1-5. (canceled)
 6. A movable scaffold, comprising: at least one fixed work platform; a frame element of the scaffold having four upright tubular corner members that extend in a longitudinal direction, and a plurality of tubular cross-members connecting the four upright tubular corner members, to define a scaffold frame; each tubular corner member having a bottom end provided with a wheel for allowing a displacement of the scaffold; between each tubular corner member and the wheel at its bottom end, a vertical adjustment element further comprising: an adjustment tube connected to said wheel, the adjustment tube mounted for longitudinal movement within said tubular corner member; a casing element mounted to said scaffold frame; and a lifting element mounted for longitudinal movement relative to the casing element, the lifting element having a bottom end provided with guide elements for displacing said one of said wheels and its associated adjustment tube relative to the tubular corner member to enable an individual vertical adjustment of said wheel relative to said upright tubular corner member and independent of every other of the four upright tubular corner members.
 7. The movable scaffold of claim 6, wherein the guide elements mounted to the bottom end of lifting elements include a tubular member, through which the adjustment tube is extended, said tubular member being linked by a bracket to a plate member mounted on the bottom end of the lifting element.
 8. The movable scaffold of claim 6 further comprising an attachment element having a bottom end, the attachment element mounted to the vertical adjustment element, the attachment element connected to the scaffold frame by a hook member mounted to the bottom end of the attachment element, wherein the hook member is in supporting engagement with one of said plurality of tubular cross-members to support from below said one tubular cross-member, and clamped to said one tubular cross-member.
 9. The movable scaffold of claim 7 wherein the lifting member is movable relative to the casing element by a mechanical or hydraulic mechanism.
 10. An assembly for mounting to a movable scaffold having at least one fixed work platform on a frame element which has four upright tubular corner members, and a plurality of tubular cross-members connecting the four upright tubular corner members, each tubular corner member having a downwardly opening bottom end, the assembly comprising: a wheel mounted to a flange; an adjustment tube mounted to the flange and extending upwardly therefrom to be received within the downwardly opening bottom end of one of the scaffold tubular corner members; a bracket element which extends outwardly from the wheel flange; a lifting element which extends upwardly from the bracket and which is spaced outwardly from the adjustment tube and parallel thereto; a tubular casing element which receives the lifting element therein; and a hook member which is adapted to bear from below against one of the horizontal tubular cross-members, the hook member being fixed to the casing element, wherein the lifting element is mounted for longitudinal movement relative to the casing element, such that a movement of the lifting element relative to the casing element can be effected mechanically or hydraulically, to thereby adjust the vertical displacement between the wheel and the scaffold corner member to which it is mounted. 